Burglar-alarm



(No Modei.)

L. K. JOHNSON; BURGLAR ALARM.

No. 458,397. V r Patented Aug 25, 1891.

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UNTTED STATES PATENT EETcE.

LOUIS K. JOHNSON, OF BROOKLYN, NEYV YORK.

BURGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 458,397, dated August25, 1891.

Application filed January 22, 1891. Serial No. 378,650. (No model.)

To aZZ whom it mag concern:

Be it known that I, LOUIS K. JOHNSON, a citizen of the United States,residing in the city of Brooklyn, in the county of Kings and State ofNew York, haveinvented certain new and useful Improvements inBurglar-Alarms, of which the following is a description sufficient toenable others skilled in the art to which the invention appertains tomake and use the same.

My invention relates to the class of devices designed to be arranged inconnection with doors and windows in such manner as to give an alarmwhen they are tampered with by the discharge of a blank cartridge, as inmy Letters Patent No. 392,805, dated November 13, 1888, upon which mypresent invention is an improvement.

The invention consists in the special construction and arrangement ofparts, hereinafter set forth, whereby a more universal adjustment andadaptation of the device is attained and whereby it is simplified andcheapened in manufacture and at the same time rendered more compact andeffective in use.

Inthe accompanying drawings, Figure 1 is a plan of my improved deviceset for use;

Fig. 2, a front elevation of the same; Fig. 3,

a central longitudinal section of the barrel of the device upon plane ofline a: on, Fig. 4, the adjoining parts being shown in elevation. Fig. 4is an end elevation taken at right angles to Fig. 2.

The device may be said to consist of three parts, the holder A, thebarrel B, and trigger O, the barrel B being supported by the holder A,While the trigger O is an independent part attached separately to eitherthe door or window-sash, or the door or window frame, as the case maybe, for it is to be understood that my device is not only equallyapplicable to doors or windows, but also that the parts areinterchangeable, in that the holder and bar rel may be attached to thedoor or windowsash, while the trigger is attached to the door or windowframe, or vice versa, as may be preferred or may be found necessary toconform to the special requirements of use. Consequently in the drawingsthe sections 1) E, to which the holder A and trigger O are respectivelyattached, may be considered to represent adjoining portions ofeitheradoorand its frame or a window-sash and its frame, the relativearrangement and operation of parts being substantially the same ineither case.

The holder A consists of a socket a, the flanges a of which afford ameans of securing it in position by screws or otherwise. Into thissocket a fits the shank or trunnion b of the barrel B, being heldtherein by a thumb-screw a which permits of its adj ustment to regulatethe degree of projection of the barrel B beyond its support. The outerend of the trunnion 19 carries a socket b, in which the body b of thebarrel rests and within which it is held adjustably by a thumbscrew 19by which the barrel may be regu lated in position with relation to thetrigger (J. The exteriors of the ends of the barrel B are formed withexternal screw-threads b b for engagement with internal screw=threadsff, formed in the caps F F, by which the ends of the barrel are closed.Both of the caps F F are perforated, one F for the reception of theblank cartridge K, which is inserted through the interior until its rimrests against the inner surface of the end of the cap, the latter beingremoved from the barrel for the purpose, and the other F for the passageof the shank of the hammer or bolt G by which the cartridge is fired.The bolt G at its inner end is formed with a nipple 01' firing-needle g,arranged to impinge upon the rim of the cartridge under the impulse ofthe spring g when the bolt Gis released from the trigger C. It will beseen that the coiled spring g rests between the shoulder g on the bolt Gand the end of the cap F, so that the bolt G has to be retracted orforced back into engagement with the trigger 0 against the resistance ofand while effecting the contraction of the spring 9, thus storing up theenergy requisite for firing the cartridge. The outer end of the bolt Gis formed with a lat eral projection g for engagement with the end 0 ofthe trigger O, and it is also provided with a handle g to facilitate itsretraction and setting upon the trigger O. The trigger is preferablyjointed, consisting of the end 0, pivotally secured by a thumb-screw cto the base 0 which is provided with lugs 0 by which it is secured inposition. The joint allows the trigger end 0 to be set with accuracy toengage the end of the bolt G. It will thus be seen that a universaladjustment of the parts with relation to each other is attained withgreat simplicity and compactness of structure and arrangement. When thedevice is set, as indicated, any slight movement of either the sectionsD or E with relation to the other is sufficient to release the bolt Gfrom the trigger C and fire the cartridge K.

What I claim as my invention, and desire to secure by Letters Patent,is-

In a detonating burglar-alarm substantially such as described,thecombination of thesockct piece a, with set-screw 0, the horizontally andlaterally adjustable holder A, having setscrew b the barrel B,firing-pin G, with the trigger-arm g and handle g', the spring 9, andthe adjustable trigger O, with standard a and set-screw c, the wholearranged and operating substantially in the manner and for the purposeset forth.

LOUIS K. JOHNSON.

Witnesses:

D. W. GARDNER,

G. T. MIATT.

